Summary

This is an updated version of mod_digest. However, it has not been
extensively tested and is therefore marked experimental. If you
use this module, you must make sure to not use
mod_digest (because they share some of the same configuration
directives).

Directives

Using MD5 Digest authentication is very simple. Simply set
up authentication normally, using "AuthType Digest" and
"AuthDigestFile" instead of the normal "AuthType Basic" and
"AuthUserFile"; also, replace any "AuthGroupFile" with
"AuthDigestGroupFile". Then add a "AuthDigestDomain" directive
containing at least the root URI(s) for this protection space.
Example:

Note: MD5 authentication provides a more
secure password system than Basic authentication, but only
works with supporting browsers. As of this writing (October
2001), the only major browsers which support digest
authentication are Opera
4.0, MS
Internet Explorer 5.0 and Amaya. Therefore, we do not
yet recommend using this feature on a large Internet site.
However, for personal and intra-net use, where browser users
can be controlled, it is ideal.

The AuthDigestGroupFile directive sets the name of a textual
file containing the list of groups and their members (user
names). File-path is the absolute path to the group
file.

Each line of the group file contains a groupname followed by
a colon, followed by the member usernames separated by spaces.
Example:

mygroup: bob joe anne

Note that searching large text files is very
inefficient.

Security: make sure that the AuthGroupFile is stored outside
the document tree of the web-server; do not put it in
the directory that it protects. Otherwise, clients will be able
to download the AuthGroupFile.

The AuthDigestQop directive determines the
quality-of-protection to use. auth will only do
authentication (username/password); auth-int is
authentication plus integrity checking (an MD5 hash of the
entity is also computed and checked); none will cause
the module to use the old RFC-2069 digest algorithm (which does
not include integrity checking). Both auth and
auth-int may be specified, in which the case the
browser will choose which of these to use. none should
only be used if the browser for some reason does not like the
challenge it receives otherwise.

The AuthDigestNonceLifetime directive controls how long the
server nonce is valid. When the client contacts the server
using an expired nonce the server will send back a 401 with
stale=true. If seconds is greater than 0
then it specifies the amount of time for which the nonce is
valid; this should probably never be set to less than 10
seconds. If seconds is less than 0 then the nonce
never expires.

The AuthDigestDomain directive allows you to specify one or
more URIs which are in the same protection space (i.e. use the
same realm and username/password info). The specified URIs are
prefixes, i.e. the client will assume that all URIs "below"
these are also protected by the same username/password. The
URIs may be either absolute URIs (i.e. inluding a scheme, host,
port, etc) or relative URIs.

This directive should always be specified and
contain at least the (set of) root URI(s) for this space.
Omitting to do so will cause the client to send the
Authorization header for every request sent to this
server. Apart from increasing the size of the request, it may
also have a detrimental effect on performance if
"AuthDigestNcCheck" is on.

The URIs specified can also point to different servers, in
which case clients (which understand this) will then share
username/password info across multiple servers without
prompting the user each time.